Rebuilding advice?

I didn't have my flywheel yet or I would've

 

Ok thanks

I had been considering just using the existing flywheel and clutch etc. but then wasn’t sure when I was reading about balancing. The reason I was considering is that the clutch felt very good and the pedal was fairly heavy (not quite like a daily driver) and I wondered if the previous owner replaced it with a quality clutch kit (there were several other upgrades). And the motor had been replaced with a used motor less than a year before I bought it. So ... perhaps the clutch was replaced then. I’ll see once it’s all apart. But of course if I have it all apart I might as well start fresh, but saving money sounds good.

 

Inspect the current parts and save money where you can.

 

99% guarantee the cylinders are out of round if the block has any more than 30k miles on it.

Like mentioned before. Honing it and just using 87.5mm pistons will not be a good idea on anything other than a new short block or a low mileage short block.

Have a machine shop check and see though.

But like mentioned for your power goals, you dont need anything crazy.

Simple Manley H beam and Manley 2618 platinum series pistons will hold 600-650whp all day and are very reliable if everything is machined, clearanced and spec'd out properly


Also. DO NOT follow Manley's recommended ring gap specs. Only their piston to wall clearance should be followed

They call for a 0.027 gap for both top and 2nd ring for anything higher than 25psi in 88mm cylinders. Which is absurdly loose and will consume oil.

I ran 0.020 top ring and 0.022 2nd ring at 36psi and 550+ whp for 85k miles before running into any oil consumption. And I beat the shit out of the car.

I'll be running 0.021 top ring and 0.024 2nd ring for my 700+whp motor

For sub 400whp, youd be ok with a 0.019 top and 0.022 2nd

Ideally on these cars you want the 2nd ring gapped 0.03 larger than the top ring.

 

i'm running a 21mm top and 24mm 2nd ring gap. this is mostly for the amount of boost you want to run this setup is good for over 21psi 3k on the motor i just rebuilt not a drop of oil consumption. she's at 24psi currently. hoping to up it shortly i'm using Mahle 4032 pistons with manley h beam rods. 88MM machinest added a half thousands clearance to the bore.

 

I’ve got the engine nearly down to where I can take it to the machine shop (there’s actually one right down the road from me, I never noticed!).

But I wasn’t sure how much to tear it down. In particular I’m curious if the thingy in the photo with the 10 bolts (not sure the part name) needs to come out. I’m assuming so, but a video I watched showing assembly had that part super clean, so I’m assuming it was either new or dunked along with the motor.

Do I take it out and bring it to the shop to be cleaned also?

 

I ended up just taking it apart. Of course I needed to to get the crank out, but I’ll bring the piece and see what they say.

Are those 10 bolts torque to yield?

 

Yeah. Take them the crank girdle to clean and inspect

I would not reuse them

 

Dropped it off at the machine shop today (http://ecamracing.com/). There was some roughing up of the crankshaft where the one bearing was toast. His initial impression was that it’s not salvageable but he said he’ll see what he can do. If it’s not then hopefully the crankshaft from my motor which broke a hole in the block is ok.

This project will be over an extended period of time but I’m looking forward to completing this first stage.

 

The machine shop said the cylinders didn’t need boring and he just dunked it and honed the cylinders. So some good news (and cheaper... ).

 

I came across someone selling some Manley H-Beam rods (5.927”), Supertech 4032 forged pistons with GMH8750 rings, and some King Engine bearings (not sure which specific ones). They are all apparently unused.

Is this suitable for what I’m wanting to do? Does anyone have suggestions for a reasonable asking price for everything?

 

Maybe a silly question...I’m just trying to think of ways to save some money.

Would it be ridiculous to get some new rods (such as Manley H-Beam) and bearings but use OEM used pistons with new rings? I have 8 OEM pistons from the two engines and don’t have any reason to think they are in bad shape (other than being used).

 

if you're gonna do it. do it right. i would not use stock pistons with forged h beam rods, i would have to add the forged pistons.

 

Ok, thanks!

Do you know anything about the Supertech 4032 pistons? The only thing I was able to find is someone saying the oil squirters need to be replaced with Gen2 because they are adjustable. I have no idea which gen motor this one is.

 

not familiar with those, i used Mahle pistons and had no issues with the Gen1 squirters

 

Can someone recommend bearings?

For the rods and also the similar looking but larger bearings for the crankshaft. (Not sure what those are called.)

 

Pretty sure people just use the Mahle Clevite bearings. Whether to get the AL or H is beyond my knowledge

 

I contacted EdgeAutoSport about piston rings and bearings.

Firstly, they said to ask the machine shop what size bearings to get (they also recommended King). Is there not a standard size for the Mazdaspeed?

Secondly, they said the rings for the Manley Platinum come a certain size and that I can’t specify what I want. So I’m assuming I’d need to order more rings separately with the 0.02 and 0.022 sizes?

Thanks.

 

Bearing spec will depend on wear on the crank / housing thicker ones or thinner will put it into spec atleast that's my understanding.

As for piston rings they can be gapped like a spark plug again my understanding (I haven't built an engine)

 

You grind down the piston rings to the spec you want. If you havent read through Johnnys build thread i highly suggest it, literally has everything you need to know.